Method for reducing deposition on back heated surface of biomass boiler

Abstract

The invention relates to the technical field of biomass boilers, in particular to a method for reducing deposition on the back heated surface of a biomass boiler. By adoption of the method, ash deposition on the back heated surface of a biomass circulating fluidized bed boiler and corrosion caused by the ash deposition can be reduced. By adoption of the method for reducing the deposition on the back heated surface of the biomass boiler, the technical defects that due to the fact that a large quantity of ash is deposited on the back heated surface of an existing biomass boiler for combustion use, the heat exchange coefficient of the heated surface and the combustion efficiency of the boiler are reduced, and corrosion is caused are overcome. According to the method for reducing the deposition on the back heated surface of the biomass boiler, the smoke temperature at an outlet of a hearth is controlled to 700-850 DEG C according to the content of alkali metals in fuel ash, and the smoke temperature at the outlet of the hearth is the average value of temperatures detected by a plurality of thermocouples arranged in a horizontal flue at the outlet of the hearth in the length direction in a dispersed mode. By adoption of the method, the ash deposition on the back heated surface of the boiler can be obviously reduced, so that the heat exchange coefficient of the heated surface and thecombustion efficiency of the boiler are ensured, and meanwhile, corrosion caused by the ash deposition is alleviated.

Description

technical field [0001] The invention relates to the technical field of biomass-fired boilers, in particular to a method for reducing deposition on the heating surface of the tail of a biomass boiler, which can reduce the deposition of dust on the heating surface of the tail of a biomass circulating fluidized bed boiler and the resulting of corrosion. Background technique [0002] When common large-scale biomass-fired boilers such as biomass circulating fluidized bed boilers are in operation, the heating surface at the rear of the boiler will absorb the heat of low-temperature flue gas, which plays an important role in reducing the exhaust gas temperature and reducing the loss of exhaust gas to improve the thermal efficiency of the boiler. Existing biomass fuels contain a large amount of alkali metal elements. During the combustion process of biomass fuels, volatile alkali metal salts in biomass will volatilize into the gas phase under high temperature conditions, and flow th...

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Problems solved by technology

[0003] The technical problem to be solved and the technical task proposed by the present invention are to overcome technical defects such as the reduction of the heat transfer coefficient of the heating surface and the combustion efficiency of the boiler caused by the deposition of a large amount of dust on the heating surface of the tail of the existing biomass boiler, as well as corrosion, and provide a reduction A method for depositing the heating surface at the tail of a biomass boiler, the method can significantly reduce the deposition of dust on the heating surface of the tail of the boiler, thereby ensuring the heat transfer coefficient of the heating surface and the combustion efficiency of the boiler, and at the same time slowing down the corrosion caused by the deposition of dust

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